Rheostat



Aug. 2s, 1923;

w. L. l BROOKS RHEOSTAT Filed Dec. 27.11921 Ivm/@f1tvf Wal Ind'L-BVOOKS; b9

HisALLor'neld- Patented Aug. 28, 1923.

UNITED STATES PATENT OFFICE.

WALLACE L. BROOKS, OF .SCHENECTADSL NEW YORK, fASSIGNOB. TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

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Application Med necember 27, 1921. Serial No. 525,234.

T 0 all whom t may concern:

Be it known that I, WALLACE L. Bnooirs7 a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of vNew York, have invented certain new and useful Improvements in Rheostats, 'of which the following is a specification.

- My invention relates to improvements in multiple unitvrheostats which are intended to be operated by a common operating means.

One of the objects of the invention is to provide an improved rheostat which may be made up of any desired number of similarly constructed units, and the invention is par ticularly directed to features whereby each unit may be made up complete and then quickly assembled wthvany desired number of other units to form a multiple unit rheostat which may be operated as a single unit by a single handle. v

In carrying my inventlon into effect, I provide a shaft for operating the contact member of each unit of the rheostat, and construct the shafts so that they each have male and female connecting portions on respective ends thereof. Each rheostat unit may be made up complete ready for assembly in a multiple unit rheostat, and when the units are assembled the male portion on the end of one shaft fits into the female portion of an adjacent shaft, so that a single assembled shaft is thusmade for' all of the units.

Other objects and advantages of my invention will be in part evident and in part pointed out particularly hereinafter in conntion with the description of an embodiment of the invention illustrated in the accompanying drawing, in which Figure 1 is a front elevational view of a rheostat unit; Fig. 2 is asectional view of a multiple unit rheostat; and Fig. 3 is a detail view of the shaft of each rheostat unit and the insulators v'which are interposed between the shafts of the respective units in the assembled shaft for all of the units.`

Referring to the drawings, a single rheostat unit comprises' an insulating base 10 on which the coiled resistance wire 11 is mounted in a suitable groove on the base. The rotatable-contact member 12 is provided for varying the effective portion of the resistor 11. This contact member is suitably secured to the shaft 13 for the rheostatr unit 10.

This shaft is provided with a projection 14 which. is adapted to register with a correspondingly shaped slot in the end of the adjacent shaft 15 of the adjacent rheostat unit 16. 'The shaft13 is provided with a suitable slot 17 on the end thereof opposite the end of the shaft carrying the rejection 1 4 for the purpose of receiving tile projection on the end of the shaft of another rheostat unit in case the rheostat is to be assembled with three or more units instead of two as shown in the drawing. Each of the shafts of the rheostat is provided with a collar 18 to which its respective contact member is secured, and the end of the shaft carrying the projection is threaded so that an internally threaded collar 19 may be secured thereon so as to frictionally hold the contact member ofthe unit and the shaft of the unit with respect to its insulating base 10.

The ends of the coiled resistor 11 of the unit are secured to suitable terminals 20 and 21,'and the terminal 23 secured to the shaft of the respective rheostat unit is provided for connection in the circuit to be controlled. The insulating block 24, of a shape corresponding to the projection 14 on the end of the shaft, is disposed over the said projection so as to fit in the slot of the adjacent shaft so as to insulate the shaft 13 from the adjacent unit. The collar 25 of Las insulating material is adapted to be slidover the connection between the two shafts so as to prevent the block 24 from working out of the slot 17.

The respective rheostat shafts are assembled in the manner shown in Fig. 2 by causing the male portion or projection of the shaft of one unit to register with the female portion or the slot in the end of the shaft of an adjacent unit so as to thereby form a single assembled shaft for all of the units. Each rheostat' unit may be made up complete ready for assembly with .an desired number of similar units in a multipleunit rheostat, all to be operated by means of the common operating handle 26. The rheostat units are suitably secured to the panel 27'* by means of the bolts 28 with insulating sleeves 29 interposed over the securing bolts so as to insulate each unit from its adjacent units.

The handle 26 for operating the assembled shaft for all of the units thus formed is provided with a shaft 27 havinga slot on adapted to register. This shaft is providedwith a screw-threaded end so that the nut 30 may be screwed thereon so as to securely hold the handle with respect to the shaft.

The button 31 of insulating material is screwed on the same end of the shaft to completely insulate the shaft.

The resistors of the various units of the rheostat may be connected in series or an multiple relation b means of the termina s heretofore referre to or the rheostat units may be connected in separate control circults so as to be simultaneously operated by the sin le handle 26.

n .accordance with the provisions of the Patent Statutes, I have described the principle of operation of my invention, together with the apparatusvwhich I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, 1s:

1. The combination in a multiple .unit rheostat of a contact member for each of said units, a shaft for each of said units for operating the contact member of the same, the said shafts having each a male vand female connecting portion on respective en ds thereof, the male portion of one shaft regis tering with the female portion of the adjacent shaft to form a continuous assembled.

shaft for allof the rheostat units, and a common operating Ameans secured to one end of thev said assembled shaft for simultaneously operating the said contact members.

2. The combination in a multiple rheostat of a contact member for each of said units, a shaft foreach ofy said units for operating the contact member of the same, 4the said shafts having each a; projection on one end thereof and a slot in the other end thereof,

the projection of one shaft registering with the slot of an adjacent shaft to form a continuous assembled shaft for all of the rheostat units, and a common handle secured to one end of the said assembled shaft for simultaneously operating the said contact members.

3. The combination in a multiple unit rheostat of a contact member for each of said units, a shaft for each of said units for operating the contact member of thesame, the said shafts having each a projection on one `end thereof and a slot in the other end thereof, the projection of one shaft registering with the slot of an adjacent shaft to form a continuous assembled shaft for all of the rheostat units, an insulator disposed over the pro'ection of each of said shafts to insulate t e respective shafts from each other, and a commorrhandle having a shaft 4with a projection and slot connection to the said assembled shaft for simultaneously operating the said contact members.

4. The combination in a multiple unit rheostat of a contact member for each of said units, a shaft for each of said units for operating the contact member of the same, a collar on one end of each of said shafts, a threaded end on the other end of each of said shafts and an internally threaded collar 0n the said other end of each of said shafts for frictionally holding the contact member and the shaft of the respective unit with respect to its respective base, the said shafts having each a projection on one end thereof and a corresponding aperture in theother end thereof, the projection of one shaft registering withthe aperture in the end of vthe adjacent shaft to form a continuous assembled shaftrfor all of the respective units,` and a common handle secured to one end of the said assembled shaft for simultaneously operating the said contact members. In Witness whereof, I have hereunto set my hand this 23rd day of December 1921.

t W. L. BROOKS. 

